C API

AddStaticFilterBack

Since 3.6.1

Available since: Windows Packet Filter 3.6.1

The AddStaticFilterBack function appends a static filter rule to the end of the driver’s active static filter table at runtime. Appended rules serve as lower-priority fallback matching rules, evaluated after all preceding filters in the table.

Syntax

BOOL WINAPI AddStaticFilterBack(
    _In_ HANDLE         hOpen,
    _In_ PSTATIC_FILTER pFilter
);

Parameters

hOpen
[in] Filter device driver handle returned by OpenFilterDriver.

pFilter
[in] Pointer to a STATIC_FILTER structure defining the matching criteria and target action.

Return Value

Returns TRUE if the filter was successfully appended; otherwise returns FALSE.

Remarks

This function sends the IOCTL_NDISRD_ADD_PACKET_FILTER_BACK control code to the driver. It provides a non-destructive way to add default-deny or broad inspection rules behind more specific filters without rebuilding the entire filter table.

See Also

AddStaticFilterFront, InsertStaticFilter, RemoveStaticFilter, STATIC_FILTER